1. Field of the Invention
The present invention relates to a driving force transmission mechanism. More particularly, this invention is concerned with a driving force transmission mechanism for a camera that uses a single motor to perform multiple driving operations; such as, film wind, film rewind, frame zoom drive, and focusing drive.
2. Description of the Related Art
In a camera having a known driving force transmission mechanism that drives the driving systems for, for example, film wind, film rewind, and frame zoom, a user operates an operation button or an operation lever on the camera in order to switch a clutch for transmitting a torque of the motor to the driving systems.
Japanese Patent Laid-Open No. 1-287547 has disclosed a drive control unit for a camera, wherein release, shutter charge, and zone change are performed with the rotation of a single motor, while film wind and film rewind are performed with the reversion of the motor.
Japanese Patent Laid-Open No. 3-81750 has disclosed a motor-driven camera, wherein film wind or shutter charge are achieved by rotating or reversing a single motor.
In some cameras, the driving systems for film wind and film rewind are driven using dedicated motors and a dedicated zoom motor.
Any of the foregoing devices requires a clutch for transmitting a torque of a motor to a selected one of the driven systems. A complex mechanism for allowing the clutch to perform switching is, therefore, needed. The complex mechanism contradicts a recent trend toward further downsizing of a camera, and leads to a cost increase due to an increase in the number of parts.
On the other hand, in a camera that is of the type driven by dedicated motors, the dedicated motors are allocated to operation mechanisms and always placed in a drive ready state. Drive can, therefore, be started swiftly. However, since multiple drive motors are required, a larger installation space is needed. This leads to a further cost increase.